From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751799AbcFYR36 (ORCPT ); Sat, 25 Jun 2016 13:29:58 -0400 Received: from mail.sig21.net ([80.244.240.74]:51426 "EHLO mail.sig21.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751757AbcFYR35 (ORCPT ); Sat, 25 Jun 2016 13:29:57 -0400 Date: Sat, 25 Jun 2016 19:29:51 +0200 From: Johannes Stezenbach To: Tetsuo Handa Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, mhocko@kernel.org Subject: Re: 4.6.2 frequent crashes under memory + IO pressure Message-ID: <20160625172951.GA5586@sig21.net> References: <20160616212641.GA3308@sig21.net> <20160623091830.GA32535@sig21.net> <201606232026.GFJ26539.QVtFFOJOOLHFMS@I-love.SAKURA.ne.jp> <20160625155006.GA4166@sig21.net> <201606260204.BDB48978.FSFFJQHOMLVOtO@I-love.SAKURA.ne.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201606260204.BDB48978.FSFFJQHOMLVOtO@I-love.SAKURA.ne.jp> User-Agent: Mutt/1.6.0 (2016-04-01) X-Spam-21-Score: -2.9 (--) X-Spam-21-Report: No, score=-2.9 required=8.0 tests=ALL_TRUSTED=-1,BAYES_00=-1.9 autolearn=ham autolearn_force=no Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Jun 26, 2016 at 02:04:40AM +0900, Tetsuo Handa wrote: > It seems to me that somebody is using ALLOC_NO_WATERMARKS (with possibly > __GFP_NOWARN), but I don't know how to identify such callers. Maybe print > backtrace from __alloc_pages_slowpath() when ALLOC_NO_WATERMARKS is used? Wouldn't this create too much output for slow serial console? Or is this case supposed to be triggered rarely? This crash testing is pretty painful but I can try it tomorrow if there is no better idea. Johannes